1. Field of the Invention
The present invention relates to a gaming medium to be used in various games and a gaming system using the gaming medium.
2. Description of the Related Art
Patent documents 1 (Japanese Published Unexamined Application No. 2004-105321) and 2 (Japanese Published Unexamined Application No. 2004-102953) disclose a technique in which, when an X-array antenna and a Y-array antenna emit radio waves, a magnetic field is generated in an upward direction vertical to a table at a cross point where the X-array antenna crosses the Y-array antenna, so as to read information stored in a wireless tag embedded in a gaming chip placed on the cross point. The technique carries out the reading operation by each batting region on the table in series.
Patent document 3 (Japanese Published Unexamined Application No. 2007-050225) discloses a technique in which reversing a gaming medium on a table is recognized by optically reading electronic watermark of the gaming medium into which a barcode is embodied. The technique carries out different output operations between the front side and the back side of a gaming medium.
In reading of information stored in a wireless tag embedded in a gaming medium, in order to recognize that either one of the front side and the back side of a gaming medium is turned up, it is considered that one wireless tag for the front side and another wireless tag for the back side are embedded in the gaming medium.
However, when the magnetically reading operation is carried out with respect to two wireless tags embedded in the gaming medium, it is possible that two pieces of information stored in two wireless tags are simultaneously read or any pieces of information stored in two wireless tags is not read. Namely, when a magnetic field generated by a reading device affects the gaming medium, electric power is supplied to two wireless tags. This allows two signals from two wireless tags to simultaneously return to the reading device. On the other hand, when a magnetic field generated by the reading device affects the gaming medium, change in inductance and/or change in resonance frequency are/is generated in two wireless tags. This prevents electronic power from being supplied to two wireless tags, which causes no signal to return to the reading device.